This retrospective cohort study was conducted at Newham University Hospital, London to investigate maternal outcome of planned vaginal delivery as well as rate of maternal-to-child transmission. Between June 2004 and June 2006, 23 (16%) women of 144 HIV-infected pregnant women opted for planned vaginal delivery. Offer of vaginal delivery was based on maternal HIV RNA count <50 cells/ml around 36 weeks' gestation. All women received antiretroviral therapy. Fifteen (65%) women achieved vaginal delivery. Babies were followed up over 18 months. All babies had antiretroviral prophylaxis. No babies were breast-fed. There was no report of maternal-to-child transmission in any of these babies. Our study suggests that planned vaginal delivery could be safe with antiretroviral therapy in pregnancy, optimal intrapartum care, viral load of <1000 copies/ml at delivery, retroviral prophylaxis for babies and avoidance of breast-feeding.